Hi Brian The MAP files contain the graphical data. It also contains style information for the objects and it contains an hierarchical spatial index - an RTREE index. Finally the header contains information from which the base unit, the bounding rectangle, and the projection can be derived.
For completeness, the DAT file contains the data attribution, the optional IND file contains 1 or more indexes on the DAT file. The ID file contains a 4 byte pointer into the MAP file to link records in DAT to their graphical representation in the MAP file. The fact a 4 byte pointer is used (signed long) is the reason a MAP file is limited to 2 GB. Also pointers in the MAP file that point into the DAT file are also only 4 bytes limiting the maximum size of the DAT file. The final TAB file is an ASCII file that describes the TABLE. When describing the Native files format it lists all fields in full. This is a more complete description than the header on the DAT file ( The DAT file header takes the form of a DBF header and does not document integer, smallint and float as done by the TAB file ). The TAB file can also describe SQL selects, links to raster and links to XLS or DBF. It is therefore possible to create a SHP file from just the MAP file. Hope this is useful to you. Regards Bob www.mapsbydesign.co.uk >I have received ESRI GIS files from my client that I am having trouble >coverting >to MapInfo, I have some SHP files which I can import successfully, however >some >files appear only to be stored in the *.MAP file format. Is there any way I >can >access the data in these files? > >If I can access MAP files do they have object data or are they just purely >graphical data (i.e. polygons, lines, etc.)? > >TIA > >Brian > >--------------------------------------------------------------------- >List hosting provided by Directions Magazine | www.directionsmag.com | >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] >Message number: 16034 > -- bob young --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 16038
